1. Field of the Invention
The present invention relates to a female terminal fitting.
2. Description of the Related Art
Male and female terminal fittings typically are connected with one another by first positioning the terminal fittings with their longitudinal axes aligned and then moving the terminal fittings toward one another. Terminal fittings of this general type are disclosed in Japanese Unexamined Patent Publication No. 4-147580. In this example, an elastic contact piece is provided in a tubular main body of a female terminal fitting by folding a side wall to extend along longitudinal direction. A male terminal fitting is inserted-into the main body from the front along the longitudinal direction. Thus, the male terminal fitting contacts and deforms the elastic contact piece. At this time, the male terminal fitting is held elastically while being squeezed between the elastic contact piece and the side wall of the main body that faces the elastic contact piece.
This connecting method requires the male terminal fitting to be inserted to a sufficient depth for the male and female terminals to be held stably in contact with each other. The time and distance over which the male terminal fitting is held in sliding contact with the elastic contact piece while being subjected to a contact pressure tends to be long. Thus, a larger force is required for the connecting operation due to frictional resistance between the sliding contact portions. Further, the sliding contact portions of the male terminal fitting and the elastic contact piece may be abraded.
As a countermeasure, the male terminal fitting can be brought into contact with the elastic contact piece sideways along the widthwise direction of the elastic contact piece. Specifically, the male terminal fitting is inserted into the main body to a position displaced laterally from the elastic contact piece. The terminal fittings then are displaced in directions such that the male terminal fitting and the elastic contact piece are brought into contact with each other. Such an arrangement can shorten the sliding contact period and distance of the two terminal fittings from the start to the end of contact as compared with male and female terminal fittings connected along their longitudinal directions. As a result, a force necessary to connect the two terminal fittings can be reduced.
However, forces generated by bringing the male terminal fittings laterally into contact with the elastic contact piece may twist and deform the male terminal fitting about its longitudinal axis. In addition, the elastic contact piece may be bent and deformed such that its longitudinal axis is shaken in the widthwise direction about the folded section at the front end of the female terminal fitting.
Upon occurrence of either situation, there is a possibility of an unstable connection between the two terminal fittings.
The present invention was developed in view of the above situations, and an object thereof is to prevent an elastic or resilient contact piece from being deformed.
The invention is directed to a female terminal fitting, comprising a main body, and at least one resilient or elastic contact piece. The main body of the female terminal fitting may be substantially tubular, and the elastic or resilient contact piece may be formed by folding a side wall of the main body back to extend in longitudinal direction. A male terminal fitting can be inserted into the main body and then brought into contact with the resilient contact piece. More particularly, the male terminal fitting initially is moved into a position in the main body where the male terminal fitting and the elastic contact piece are laterally offset and spaced from one another. The male terminal fitting and/or the resilient contact piece then are displaced laterally or transversely relative to one another and into a position where the male terminal fitting is in contact with the resilient contact piece.
The resilient contact piece may comprise at least one twist-restricting portion that can be brought into contact with a side wall of the main body to prevent the resilient contact piece from being twisted about its longitudinal axis as the male terminal fitting is brought into contact with the resilient contact piece. Accordingly, a twisting of the resilient or elastic contact piece due to the frictional force of the male terminal fitting can be prevented effectively.
The twist-restricting portion preferably may be configured to contact a portion of a side wall of the main body that bulges toward the resilient contact piece. Additionally, the twist-restricting portion may comprise at least one projection that projects laterally from the resilient contact piece.
The width of the contact area of the elastic contact piece with the side wall can be made larger than the width of the elastic contact piece by holding the twist-restricting portion in contact with the side wall at a position that extends laterally from the elastic contact piece. Thus, the elastic contact piece can be prevented from being twisted and deformed about its longitudinal axis as the male terminal fitting is brought into contact with the elastic contact piece from a laterally displaced position.
The resilient contact piece may comprise at least one shake-restricting portion instead of the twist-restricting portion. The shake-restricting portion can be brought into contact with a wall surface of the main body at a back side with respect to the displacing direction of the male terminal fitting relative to the resilient contact piece. The contact of the shake restricting portion with the wall surface of the main body prevents the elastic contact piece from being bent and deformed such that its longitudinal axis is shaken in the widthwise direction as the male terminal fitting is brought laterally into contact with the elastic contact piece.
In a preferred embodiment, the elastic contact piece may comprise both a twist-restricting portion and a shake-restricting portion. The twist-restricting portion can be brought into contact with the side wall at a position extending out along widthwise direction and can prevent the elastic contact piece from being twisted about its longitudinal axis as the male terminal fitting is brought into contact with the elastic contact piece. The shake-restricting portion can be brought into contact with a wall surface of the main body at a back side with respect to the displacing direction of the male terminal fitting relative to the elastic contact piece and can prevent the elastic contact piece from being displaced such that the longitudinal axis of the elastic contact piece is shaken in the widthwise direction.
The contact of the twist-restricting portion and the shake-restricting portion with the wall surface of the main body prevents the elastic contact piece from being twisted about its longitudinal axis and from being bent such that its longitudinal axis is shaken in widthwise direction as the male terminal fitting is brought laterally into contact with the elastic contact piece.
Preferably, the resilient contact piece is angled to define a peak substantially at the longitudinal center.
The resilient or elastic contact piece may comprise a guiding portion for guiding the displacement of the male terminal fitting. The guiding portion can smoothen both a contacting action of the male terminal fitting with the elastic contact piece and an elastic deformation of the elastic contact piece.
The main body may include an accommodation space offset laterally from the resilient contact piece. The male terminal fitting may be inserted in a first direction into the accommodation space and brought into contact with the resilient contact piece along a second direction arranged at an angle to the first direction.
The main body may comprise a protection wall partially covering the resilient contact piece to prevent the male terminal fitting from being inserted into a space of the main body where it cannot resiliently contact the resilient contact piece.
Most preferably, the male terminal fitting is insertable between the resilient contact piece and a second side wall. The second side wall preferably comprises an inwardly bulging portion that at least partly substantially faces the resilient contact piece.
These and other objects, features and advantages of the present invention will become apparent upon reading of the following detailed description of preferred embodiments and accompanying drawings.